Structural members for building construction



R. BIFFANI Aug. 13, 1 968 STRUCTURAL MEMBERS FOR BUILDING CONSTRUCTION 5Sheets-Sheet 1 Filed Oct. 5, 1965 "I"ll",lplllllalalllllllppfi INVENTOR.2.131; ffah Gh ATTO kNE'S Aug. 13, 1968 R. BIFFANI 3,396,499

STRUCTURAL MEMBERS FOR BUILDING CONSTRUCTION Filed Oct. 5, 1965 3Sheets-Sheet 2 llll l INVENTOR.

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Bdffani BY 6.14% out 01m ATT'O n-NGas United States Patent 3,396,499STRUCTURAL MEMBERS F812 BUILDING CONSTRUCTTGN Raifaele Bitfani, ViaCineto Romano 45, Rome, itaiy Filed Oct. 5, 1965, Ser. No. 493,097 2Claims. ((31. 52127) ABSTRACT OF THE DISCLGSURE A beam of a building issubstantially square in cross section and is provided at its cornerswith opposite inclined surfaces forming channels and ridges ortriangularly shaped extensions. The butt joining of these beams iseffected by pairs of hinged arms having ends or fins which are forced byscrews into firm engagement with the beams.

The present invention concerns structural buildings more especiallymetal frames and more generally the carpentry work thereof so as tosolve the problem of the weight and dimensions of the separate membersof a structure in the most satisfactory way.

Obviously the first and most important problem to be solved is that ofthe load-bearing beams.

According to the present invention, the load-bearing beams are formed ofa single type of structural shape adapted to be connected to the othermembers of the structure, inasmuch as the beam is provided with aplurality of dovetails each of which occupies a longitudinal face of thestructural shape.

In one embodiment of the invention the beam has a substantially squarecross-section with four triangular appendixes at the four cornersthereof, each of the corners being integrally attached to the midpointof the base of each of the triangular appendixes. The four dovetailsformed as above are suited for all the connections and joints of thebeam to other structural shapes as required for obtaining any other,structure, as it will be made clearer hereinafter.

The invention will now be described further, by way of example, withreference to the accompanying drawings, in which:

FIG. 1 is a cross-section through a preferred embodiment of beamconstructed in accordance with the invention;

FIG. 2 is a dovetail, in perspective, showing the means for attachingtogether a horizontal beam, a vertical beam and another horizontal beamperpendicular to the former horizontal beam;

FIG. 3 is a detail in perspective showing a connection between asupporting pillar and two horizontal orthogonal beams and the method forretaining, fastening and locking them without supplementary means, aswell as insulating or sealing panels, fioor ceiling or roof panels, orpartitions;

FIG. 4 is a perspective view showing the jointing of two superimposedorthogonal beams;

FIG. 5 is a diagrammatical View of a roof supporting framework;

FIG. 6 is a detail of the clamp for fastening a beam onto a foundationsill;

FIG. 7 is a cross-section through another form of beam;

FIG. 8 is a detail of a clamp for connecting the end of a structureperpendicular to a beam, when the latter is in the form of a beam of thetype shown in FIG. 7; and

FIG. 9 is a detail of the clamp shown in FIG. 2.

The profile of the main member of the structure shown in FIG. 1,comprises a tube 10 of substantially square cross-section at the cornersof which four triangles are located in such a way that the points ofattachment of the 3,396,499 Patented Aug. 13, 1968 corners with thetriangles are at midpoint of the greater sides 14 of the latter whichwill be referred to as the base of the triangle. The structural shape ofthe beam members can be produced -by means of known forming machines; byhot or cold drawing, extrusion, rolling, welding, or in any other way.Furthermore the beams can be made of light alloy or synthetic resin.

FIG. 2 shows how a beam A is butt jointed to one of the faces of anotherbeam B perpendicularly thereto, by means of a clamp which includes twofiat arms with suitably bent ends for engaging the inner oblique sides1'4 of the dovetail. The end of each of the arms opposite to thedovetail engaging end is formed as an eye which extends for half thewidth of the arm, 18, 18'. A pin 22 is inserted through the eye of botharms to form a hinge. The ends of the pin extend through two oppositeholes 22 in the side walls of the beam A, whereby the end of the latteris fastened to beam B.

A screw 24 with round head 26 in which an hexagonal recess is formed forreceiving a wrench to drive it, is screwed into a nut which is welded onthe inner face of arm 13; the free end of the screw bears against theinner side of the other arm 18' whereby the two lower edges of the arms18, 18 are forced into firm engagement with the oblique faces of thedovetail. The ends of pin 22, which extend through holes on oppositewalls of the beam A, prevent any movement of the latter with respect tobeam B.

In FIGS. 2 and 9 a second type of clamp is shown for butt jointing abeam B to a similar beam C. This second type or" clamp comprises aU-shaped plate 28, that is a plate with two parallel sides and a thirdside perpendicular to the former two and connecting them to each other.The two parallel sides are cut away at the corners adjacent to the thirdside, whilst the latter is narrower than the other two, this being madefor the purpose of introducing the third side into the dovetail of abeam so that the whole outside surface of the third side lies againstthe fiat surface of the dovetail.

Between the two parallel sides of the U-shaped plate and crosswise tothem, there are inserted a pair of elements similar one to the other;these elements are bent along a line which divides them into twoportions or sides which form a dihedral 36; one of the two sides of thedihedral has a fin 3% attached to the edge thereof for engaging theoblique face 14 of the dovetail; a triangular end plate 32 is welded ateach end of each dihedral to prevent any widening of the dihedrals angleunder the stresses exerted on said elements. The two dihedrals arepositioned in the U-shaped plate 28 in such a Way that, Whilst fins 3dengage the dovetail oblique surfaces at the edge of one side of eachdihedral the other side faces the corresponding side of the otherdihedral; the outside corners of the two dihedrals meet along a lineabout which the two dihedrals can rock across a small angle.

A firm hold of fins 36 with the dovetail oblique faces is achieved bymeans of a screw 34 which forces the sides of the two dihedrals whichface one another, because the outside corners 33 of the dihedrals meetalong the same line, so that the dihedrals are compelled to rotate aboutthe line, and the fins are forced inside the dovetail. A pin 22 extendsthrough two holes in the opposite faces of beam C and throughcorresponding holes in the sides of the {U-shaped plate 28; this pinensures the connection of beam C to the U-shaped plate; the third sideof the latter is trapped under fins 3i) and firmly held against beam Bthereby ensuring the joint between the two beams.

A third form of clamp for connecting two superimposed orthogonal beamsis shown in FIG. 4 and comprises a plate with a flat face 36 and achannel shaped portion 37 which clings on the triangular corners 12 ofthe beam and mates with the profile thereof. This type 3 of clamp isinstalled on an underplate 39 by means of screws 38. The underplate 39is long enough to eXtend under plate 36 and under the plate symmetricalto plate 36 at the other side of beam B.

The holes on plate 36 through which screws 38 are inserted, arepreferably of elongated form in order to facilitate the assembly of thejoint components.

FIG. 4 also shows a fourth type of joints for the structure. This jointcomprises an iron plate 40 which acts as a butt strap; the parallellongitudinal edges of the plate are bent to form a pair of elongatednarrow fins to be inserted into holding engagement on a correspondingsection of the dovetail. J

The butt-strap plate is provided with two or more holes for receiving asmany screws as engage a corresponding threaded hole on the beam face,the screws are alternately of the self-tapping type, whereby the plateis fastened to the two aligned beams E and E and the latter are buttjointed together. These butt-strap plates are obviously 4 applied to allof the faces of the two beams flee from obstructions. 1 Q l t The clampshown in FIG. 8 is similar to that shown in FIG. 2 and its use is forbutt jointing a vertical beam C triangle, said dovetail portionconsisting of a dovetail channel located between each adjacent pair oftriangles and having oblique side faces, means forming a butt joint ofone of said members with the other one of said members and comprising apair of flat arms; a pin hingedly connecting said arms at one end, athrusting screw, the

arms being forced apart by said thrusting screw "so that the ends of thearms opposite to the pin are forged into holding engagement with saidoblique side faces of the dovetail channel, said pin extending throughholes on the opposite sides of one of said members so as to prevent anymovement thereof with respect joinedv thereto. 4

. 2. A constructional element comprising at least two hollow members ofsubstantially square cross section extending at right angles to eachother, each of said members having each face withla pair of oppositelyfacing longitudinally extending surfaces to define on each face alongitudinally entending dovetail portion, the member including fourtriangles, one at each of the four corners thereof, the connection ofeach triangle to the faces of the member being at the midpoint of oneside of the triangle, said dovetail portion consisting of a dovetailchanto a horizontal beam F. In the case of the FIG. 8 clamp it mustcling to a projection dovetail, instead of a recessed dovetail of thetype shown in FIG. 2, the edges of arms 48 and 48, which correspond toarms 18 and 18' of the clamp shown in FIG. 2 are bent-inwardly insteadof outwardly and, in order to make a firm holding enachieved between thearm ends and the oblique faces of the dovetail.

FIG. 6 shows, as already mentioned, a detail of the clamp for fasteninga beam into a foundation sill. The clamp 36 is attached to an anchoringstrap 37 buried into the sill by means of the same screw 38 which forcesthe clamp 36 into holding engagement with the beam.

FIG. 3, and 5 show diagrammatically how the roof and the floor elementsof a building can be connected with the beam and how panels 42 ofsuitable material can be installed by skillful use of the abovedescribed clamps.

Obviously the dimensions of the panels and consequently the distancebetween two successive beams which hold a row of panels, will bedetermined according to the load to be supported by the structure.

I claim:

1. A constructional element comprising at least two hollow members ofsubstantially square cross section extending at right angles to eachother, each of said members having each face with a pair of oppositelyfacing longitudinally extending surfaces to define on eachface alongitudinally extending dovetail portion, the member including fourtriangles, one at each of the four corners thereof, the connection ofeach triangle to the faces of the member being at the midpoint of one'side of the nel located between each adjacent pair of triangles andhaving oblique side faces, means forming a butt joint of one of saidmembers with the other one of said members and comprising two similarangular plates for butt joining l the two members, said plates being injuxtaposition, whereby'two corresponding sides of the plates face oneanother and the other two sides of the same plates diverge, two finsprovided at the edges of said other two sides and engaging said obliqueside faces of the dovetail channel, a screw forcing the two facing sidestoward each other, the two otuside corners of the angular platesabutting one against the other, whereby the two fins are forced into thedovetail channel, a U-shaped plate, the two angular plates beinginserted crosswise between two sides of said U-shaped plate, the thirdside of the U- shaped plate lying against a surface of the dovetailchannel underneath the fins and being held firmly by the fins, and a pinconnecting the other two sides of the U-shaped plate to said othermember, said pin extending through holes formed in the sides of theU-shaped plates and through holes formed on the opposite sides of saidother member.

' References Cited OTHERREFERENCES 1,055,793 German Printed Application.

FRANK L. ABBOTT, Primary Examiner. ALFRED C. PERHAM, Assistant Examiner.

to the other member butt

